This page left blank intentionally

Transcription

1 333

2 This page left blank intentionally

3 Senate Bill 1398 Response Coal Combustion Residuals Ash Pond Closure Assessment Prepared for: Dominion Energy 5000 Dominion Blvd Glen Allen, VA Prepared by: 4840 Cox Road Glen Allen, VA T: +1 (804) F: +1 (804) aecom.com

4 This page left blank intentionally

5 Executive Summary Coal ash, also referred to as coal combustion residuals (CCR), is stored in surface impoundments (ash ponds) and in dry landfills. Following large coal ash spills with environmental impacts in Tennessee (2008) and North Carolina (2014), the U.S. Environmental Protection Agency (USEPA) established national rules for coal ash storage and strengthened existing controls to ensure the long-term safety and structural integrity of existing ash ponds to help prevent future releases. On April 17, 2015, the USEPA issued the Final CCR Rule, which establishes regulations for the management of CCR in ash ponds and landfills as well as for beneficial use (recycling/reuse). The CCR Rule was incorporated into the Virginia Solid Waste Management Regulations (VSWMR) on January 27, By adopting the CCR Rule, the Virginia Department of Environmental Quality (DEQ) is authorized to issue solid waste permits to govern the closure of regulated CCR units in Virginia. Through permitting and regulatory programs, Virginia has implemented rules that are more comprehensive than the federal rules. The DEQ regulates solid waste and water discharge related to ash ponds, and the Virginia Department of Conservation and Recreation regulates the structural integrity of ash ponds. The Virginia General Assembly enacted Senate Bill 1398 (SB 1398) on April 5, 2017, to require a study of all ash ponds in the Chesapeake Bay watershed and determine available closure options that would effectively manage these ponds in accordance with applicable state and federal regulations, while ensuring that the safety, environmental, and community impacts of the pond closures are managed. The objective of the study was to comply with the following SB 1398 requirements: Evaluate closure by removal with recycling or reuse (beneficial use) of the CCR material Evaluate closure by removal with placement of CCR material in a permitted landfill Evaluate closure-in-place addressing long-term safety, structural, and extreme weather event resiliency Describe groundwater and surface water quality surrounding each ash pond and evaluate corrective measures if needed SB 1398 is applicable to eleven ash ponds at four Dominion Energy (Dominion) power stations, as shown in Table ES-1. On behalf of Dominion, conducted a study consisting of an evaluation of the groundwater and surface water for all eleven ponds and an assessment of closure options for the five of the eleven ponds that have been slated for closure. Ash has been removed or is in the process of being removed from the other six ponds; therefore, these ponds are being closed by removal. This report presents the results of the study and also describes historical pond closure and closure trends across the U.S. power industry. Ash ponds can be closed by removing the CCR materials or closing the pond in place. Closure by removal options include recycling/beneficial use or relocation of CCR to a lined, permitted landfill. Potential landfill options include expansion of an existing on-site landfill, construction of a new on-site landfill, transporting the materials off site to a permitted commercial landfill, or transporting the materials off site to a new landfill that would need to be permitted and constructed. ES-1

6 Power Station Bremo Power Station Chesapeake Energy Center Chesterfield Power Station Possum Point Power Station (1) (3) CCR Units Table ES-1: Ash Ponds included in the Study (2) North Ash Pond East Ash Pond Remaining CCR Volume (CY) (1) 4,800,000 1,400,000 Operating Status Slated for closure Ash being actively removed and transported to North Ash Pond Area (acres) West Ash Pond 0 Ash removed 22 Bottom Ash (2) Pond (2) Lower Ash Pond (2) Upper Ash Pond Ash Pond A Ash Pond B Ash Pond C 60,000 Committed to closure by removal 5 3,600,000 11,300,000 Slated for closure Slated for closure 40,000 Residual ash to be removed from Ash Ponds A, B, and C and transported to Ash Pond D (2) Ash Pond D 4,009,250 Slated for closure 70 Ash Pond E 2,250 Residual ash to be removed and transported to Ash Pond D Total Volume 25,211,500 CCR volumes are based on Dominion estimates as of July 10, 2017 (2) Assessed for closure options (3) While not subject to the assessment required by SB 1398, the CCR landfill at the Chesapeake Energy Center is slated for closure in accordance with VSWMR. Virginia DEQ issued a draft solid waste permit in June 2016 for closure of the landfill, which process was later suspended at Dominion s request. The draft permit required Dominion to evaluate and propose alternative corrective measures to address groundwater impacts. In addition, in connection with a July 31, 2017, court order, Dominion will submit a revised solid waste permit application to DEQ by March 31, 2018, to include proposed additional corrective measures to address site-wide groundwater impacts. CCR = coal combustion residuals; CY = cubic yards; DEQ = Department of Environmental Quality; VSWMR = Virginia Solid Waste Management Regulations Summary of Findings Various closure options could be implemented at each station to address the safety, environmental, and community impacts related to the ash ponds. All of the options have inherent challenges, risks, schedules, and costs. For the larger volume ponds at Bremo, Chesterfield, and Possum Point Power Stations, removal options compared to closure-in-place would generally take longer and include off-site transportation that would introduce additional safety, environmental, and community impacts. Closure by removal costs for these ponds would also be an order-of-magnitude larger than closure-in-place. CCR materials from smaller volume ponds such as the Chesapeake Energy Center Bottom Ash Pond could be removed in shorter durations with fewer safety, environmental, and community impacts. Dominion has committed to removing the materials from the Chesapeake pond for beneficial use or offsite disposal. Preliminary groundwater results indicate that CCR constituent concentrations were detected above USEPA Maximum Contaminant Levels (MCLs) or background levels in groundwater monitoring wells associated with the ash ponds at all four stations. Additional monitoring is required before these results are confirmed. However, the detections were isolated to areas adjacent to the ash ponds and do not affect drinking water supplies. Additionally, surface water data indicate that all constituent concentrations are below Virginia Surface Water Quality Standards (aquatic and human health) at each of the four stations. Based on the groundwater data and site-specific conditions, various potential corrective ES-2

7 measure technologies could be implemented in conjunction with closure-in-place to address the groundwater conditions surrounding the ash ponds. The findings of the study are summarized below: Beneficial Use The beneficial use market study indicated a projected regional excess of ash supply that would result in recycling options for the large volume of ponded coal ash having prolonged time frames for processing and placement in the marketplace. Many potential beneficial use technologies were evaluated to assess the feasibility of processing ponded ash. Although this market is rapidly evolving, many technologies are still in the research stage or are unproven for large-scale coal ash beneficiation. Four potentially viable technologies were further evaluated for coal ash quality requirements, processing duration, costs, and other considerations. None of the unprocessed CCR materials sampled from the ash ponds met all of the ASTM International specifications for beneficial use in concrete; additional processing may be needed for the ash to be beneficially used, and some of the material unsuitable for beneficiation may require landfill disposal. to On-Site Landfill The feasibility of either expanding an existing on-site landfill or constructing a new on-site landfill cell was evaluated adhering to state and federal siting requirements. None of the power stations have existing landfills that could be expanded to meet these requirements, nor do any stations have available space to meet requirements for constructing a new landfill. Chesterfield and Possum Point Power Stations could potentially site a new landfill on the footprint of existing ash ponds, but only if the DEQ and local authorities grant a variance for setback requirements from county roads. to Existing Off-Site Permitted Landfill Several commercial solid waste landfills are within 50 miles of the Bremo, Chesapeake, and Chesterfield stations, while the closest suitable landfill to Possum Point is approximately 100 miles away. There are limited landfills with the permitted capacity to accept the large volumes of CCR from the Dominion stations. This evaluation considered landfills within a 50-mile radius of the power stations for transportation logistic practicalities. Landfills beyond 50 miles could be considered but costs would increase. to New Off-Site Landfill A new centrally located off-site landfill could be developed, designed, and constructed to manage coal ash from the three Dominion stations. This option would likely be more costly than hauling the ash to existing, permitted landfills. Transporting CCR Off-Site by Truck or Rail CCR from Bremo, Chesterfield, and Possum Point could be transported by truck or by rail. Based on the limited ash volume at Chesapeake, trucking would be most cost-effective and practical at Chesapeake. Both hauling options present safety, environmental, and community considerations with differing durations and costs. Rail transportation would require significant infrastructure upgrades at Chesterfield and Possum Point Power Stations. Transporting CCR Material Off-Site by Barge Barge options are not feasible at Bremo (shallow river), Chesapeake (small volume), or Chesterfield. Barging from Chesterfield would require extensive infrastructure upgrades, and after the CCR was barged 18 miles downriver, it would then have to be loaded onto trucks and hauled 12 miles to the closest landfill. That landfill is 29 miles by truck from the Chesterfield Power Station, and another landfill is only 7 miles from the Chesterfield Station. CCR could potentially be barged from Possum Point down the Potomac River to the Chesapeake Bay and up the James River to the Port of Weanack in Charles City County. To ES-3

8 implement the barge option, DEQ regulations require certified watertight containers that would be loaded and unloaded on barges by crane, and moving the ash to the disposal facility would require that the CCR material be loaded on trucks and transported 18 miles on public roads to the landfill after the barge was unloaded. The infrastructure upgrades and extensive requirements would make this option significantly more expensive than transport by truck or rail. Closure-in-Place Existing closure-in-place designs at all four power stations would provide structural integrity of the CCR units by addressing the long-term risks described in the closure plans, meeting siting requirements, and having the ability to withstand extreme weather events (including flooding, hurricanes, storm surges, and erosive forces) and earthquakes. Industry-Wide Compliance Efforts Based on national data available on CCR websites and other publicly available data, as of September 2017, there were approximately 500 ash ponds in the United States covering a total of more than 23,500 acres and storing a total of more than 1 billion cubic yards (CY) of CCR material. Closure-in-place is being pursued for more than 93% of ponds with CCR volumes greater than 5 million CY and 75% of ponds between 1 and 5 million CY and more than 80% of ash ponds larger than 20 acres. Closure by removal has generally been reserved for low volume (less than 1 million CY) and small acreage (less than 20 acres) ash ponds. Currently, there are approximately 140 ash ponds in the southeastern United States (Alabama, Florida, Georgia, Kentucky, Mississippi, North Carolina, South Carolina, Tennessee, Virginia, and West Virginia). Of these ponds, more than 92% with CCR volumes greater than 5 million CY and more than half of ponds with between 1 and 5 million CY are being closed in place. Sixty-seven percent (67%) of ash ponds with CCR volumes of less than 1 million CY are being closed by removal. Similarly, more than 70% of ash ponds with more than 100 acres and more than 55% between 20 and 100 acres are being closed in place. More than 65% of the smaller ash ponds (less than 20 acres) are being closed by removal. Closure Options This report evaluates the following key considerations for ash pond closure alternatives: Regulations all federal, state, and local regulations and requirements must be met Risk potential safety, environmental, and community impacts are described Feasibility all options must be technically feasible Schedule the duration of the option directly affects the safety and community impacts; some of the option durations exceed the compliance schedule set forth by the CCR Rule Cost costs for each option are provided Tables ES-2 through ES-5 summarize the closure options that were assessed for the four Dominion power stations, including the anticipated length of time to complete the option, estimated cost, and implementation considerations. Table ES-6 provides similar information for a potential new regional off-site landfill that would be designed to manage coal ash from the Bremo, Chesterfield, and Possum Point Power Stations. ES-4

9 Costs are Class 5 estimates (+100%, -50%) that include taxes, overhead, escalation, contingency, and typical contractor mark-ups to reflect potential market values for the corresponding closure options over their full durations. The estimates are preliminary and represent s opinion of the probable costs based on information available at the time of this study. Actual costs may vary significantly if market conditions and pricing assumptions change. Table ES-2: Summary of Closure Options for Bremo Power Station Closure Option Est. Time Frame Est. Cost (1) Implementation Considerations 11 to 27 $593M to and Beneficial Use years $1.34B Ash pond stays open for 11+ years (3 years design/permit/construct, remaining years to transport), increases safety risk, and results in prolonged duration for dewatering/water treatment Duration to implement several evaluated technologies exceeds CCR closure requirements of 15 years Time frames are driven by available market and throughput of beneficiation technologies Safety and community risks from excavation and over-theroad hauling due to significant volume, multi-year duration removal project; up to 150 trucks/day each way for 8+ years Truck traffic may result in increased noise, emissions, traffic congestion, vehicle accidents Greater potential for groundwater migration during CCR removal and On-Site Landfilling and Off-Site Commercial Landfilling by Truck and Off-Site Commercial Landfilling by Rail NA NA Alternative not feasible because there is no location to temporarily store materials during new landfill construction 13 years $1.03B Ash pond stays open for 13 years (1 year design/permit/ construct, remaining to transport), increases safety risk, and results in prolonged duration for dewatering/water treatment Safety and community risks from excavation and over-theroad hauling due to significant volume and multi-year duration removal project (150 trucks/day each way for 12 years; truck leaving site approximately every 3 minutes for 10 hours/day Monday through Friday) Truck traffic may result in increased noise, emissions, traffic congestion, vehicle accidents Greater potential for groundwater migration during CCR removal 10 years $1.53B Ash pond stays open for 10 years (2 years design/permit/ construct, remaining transport), increases safety risk, results in prolonged duration for dewatering/water treatment Safety and community risks from excavation and rail hauling due to significant volume and multi-year duration removal project (200+ railcars per week for 8 years) Reduced hauling risks for rail vs. trucking Greater potential for groundwater migration during CCR removal ES-5

10 Closure Option and Off-Site Commercial Landfilling by Barge Closure-in-Place with Potential Groundwater Corrective Measures (1) Table ES-2 (cont.): Summary of Closure Options for Bremo Power Station Est. Time Frame Est. Cost (1) Implementation Considerations NA NA Alternative not feasible due to shallow depth of James River 3 to 5 years $98M to $173M No impacts for CCR removal or off-site hauling Lowest risk for safety, community, schedule, and cost Lower groundwater migration potential for CCR remaining in place once closure is complete, which is addressed by corrective measures Includes cost range for corrective measures 2-year corrective measure construction duration Estimated 10- to 30-year duration for groundwater corrective measures All costs in this report are Class 5 estimates (+100%, 50%) and represent opinions of probable cost based on information available at the time of this study. is not responsible for any variance from costs presented in this document or actual prices and conditions obtained. CCR = coal combustion residuals; B = billion; M = million; NA = not applicable Table ES-3: Summary of Closure Options for Chesapeake Energy Center Closure Option Est. Time Frame Est. Cost (1) Implementation Considerations Up to 1 $10.6M Safety and community risks from over-the-road hauling (25 to and Beneficial Use year 90 trucks per day intermittently for up to 1 year) Increased noise, emissions, truck traffic, accident potential Greater potential for groundwater migration during CCR removal Market risks (there may be insufficient demand) NA NA Dominion has committed to removing the CCR materials from and On-Site Landfilling the Bottom Ash Pond at the Chesapeake Energy Center Landfill no longer receiving ash 2 to 3 $13.3M Safety and community risks from over-the-road hauling and Off-Site Commercial months Increased noise, emissions, truck traffic, accident potential Landfilling by Truck and Off-Site Commercial Landfilling by Rail and Off-Site Commercial Landfilling by Barge NA NA Alternative not practical due to small volume of CCR NA NA Alternative not practical due to small volume of CCR Potential Groundwater 3 to 5 years $2.4M to Dominion has committed to removing the CCR materials from Corrective Measures for $161M the Bottom Ash Pond at the Chesapeake Energy Center the Peninsula Corrective action will be necessary for the peninsula (1) All costs in this report are Class 5 estimates (+100%, 50%) and represent opinions of probable cost based on information available at the time of this study. is not responsible for any variance from costs presented in this document or actual prices and conditions obtained. CCR = coal combustion residuals; M = million; NA = not applicable ES-6

11 Closure Option Table ES-4: Summary of Closure Options for Chesterfield Power Station Est. Time Frame Est. Cost (1) 21 to 53 $1.49B to and Beneficial Use years $4.25B Implementation Considerations Ash pond stays open for 21+ years (3 years design/permit/ construct, remaining transport), increases safety risk, and results in prolonged duration for dewatering/water treatment 21+ years duration to implement exceeds CCR closure requirements of 15 years The time frames are driven by the available market and throughput of beneficiation technologies Safety and community risks from over-the-road hauling due to significant volume and multi-year duration removal project; up to 150 trucks per day each way for 18+ years Truck traffic may result in increased noise, emissions, traffic congestion, vehicle accidents Greater potential for groundwater migration during CCR removal 20 years $1.28B Ash pond stays open for 20 years, increases safety risk, and and On-Site Landfilling results in prolonged duration for dewatering/water treatment 20 years duration to implement exceeds CCR closure requirements of 15 years Only feasible if the DEQ and local authorities grant a variance to allow the setback from the road to be reduced from 500 to 100 feet; the presence of Henricus Park and Aiken Swamp adjacent to the area in question would need to be considered in this determination Eliminates risks associated with off-site hauling, truck traffic Greater potential for groundwater migration during CCR removal Engineering challenges for CCR dewatering, excavation, and staging 29 years $2.68B Ash pond stays open for 29 years (1 year design/permit/construct, and Off-Site remaining transport), increases safety risk, and results in Commercial Landfilling prolonged duration for dewatering/water treatment by Truck 29 years duration to implement exceeds CCR closure requirements of 15 years Safety and community risks from over-the-road hauling due to significant volume and multi-year duration removal project (150 trucks per day each way for 28 years; truck leaving site approximately every 3 minutes for 10 hours per day Monday through Friday) Truck traffic may result in increased noise, emissions, traffic congestion, vehicle accidents Greater potential for groundwater migration during CCR removal ES-7

12 Table ES-4 (cont.): Summary of Closure Options for Chesterfield Power Station Closure Option Est. Time Frame Est. Cost (1) Implementation Considerations and Off-Site Commercial Landfilling by Rail and Off-Site Commercial Landfilling by Barge 24 years $4.63B Ash pond stays open for 24 years (4 years design/permit/construct, remaining transport), increases safety risk, and results in prolonged duration for dewatering/water treatment 24 years duration to implement exceeds CCR closure requirements of 15 years Safety and community risks from excavation and rail hauling due to significant volume and multi-year duration removal project (200+ railcars per week for 20 years) Reduced hauling risks for rail vs. trucking Increased noise, emissions, accident potential Greater potential for groundwater migration during CCR removal N/A N/A Alternative not practical Virginia regulations require sealed containers that would need to be loaded onto and off of barges by crane, requiring infrastructure construction at both ends Disposal facility not adjacent to barge unloading facility; requires barging for 20 miles, unloading of containers, transfer materials to trucks, and additional 20 miles of truck hauling to landfill after unloading barge Same disposal facility is only 29 miles by truck from Chesterfield Power Station, while another facility is only 7 miles away from the station Closure-in-Place with Potential Groundwater Corrective Measures 3 to 5 years $246M to $1.11B No impacts for CCR removal or off-site hauling Lowest risk for safety, community, schedule, and cost Lower groundwater migration potential for CCR remaining in place once closure is complete, which is addressed by corrective measures Includes cost range for corrective measures 2-year corrective measure construction duration Estimated 10- to 30-year duration for groundwater corrective measures New Regional Off-Site Landfill for Ponds at Bremo, Chesterfield, and Possum Point 21 years $4.15B Would be located in a centralized area to accept materials from all Dominion ash ponds Ash ponds stays open for up to 20 years (6 years design/permit/construct new landfill, remaining time to transport from all three sites), increases safety risk, and results in prolonged duration for dewatering/water treatment Duration will exceed CCR closure requirements of 15 years at Chesterfield Power Station Safety and community risks from excavation and over-the-road hauling due to significant volume, multi-year duration removal project (up to 150 trucks/day each way from all 3 stations for 15+ years) Truck traffic may result in increased noise, emissions, traffic congestion, vehicle accidents Construction of new landfill and hauling ash to new location will affect local communities Extensive permitting and design required (1) All costs in this report are Class 5 estimates (+100%, - 50%) and represent opinions of probable cost based on information available at the time of this study. is not responsible for any variance from costs presented in this document or actual prices and conditions obtained. B = billion; CCR = coal combustion residuals; DEQ = Virginia Department of Environmental Protection; M = million; NA = not applicable ES-8

13 Table ES-5: Summary of Closure Options for Possum Point Power Station Closure Option Est. Time Frame Est. Cost (1) Implementation Considerations 8 to 17 years $471M to and Beneficial Use $899M Ash pond stays open for 8+ years (3 years design/permit/construct, remaining transport), increases safety risk, and results in prolonged duration for dewatering/water treatment Duration to implement several evaluated technologies may exceed CCR closure requirements of 15 years The time frames are driven by the available market and throughput of beneficiation technologies Safety and community risks from excavation and over-theroad hauling due to significant volume, multi-year duration removal project (up to 150 trucks/day each way for 5+ years) Truck traffic may result in increased noise, emissions, truck traffic, and vehicle accidents Greater potential for groundwater migration during CCR removal and On-Site Landfilling and Off-Site Commercial Landfilling by Truck 8 years $380M Ash pond stays open for 8 years, increases safety risk, and results in prolonged duration for dewatering/water treatment Only feasible if the DEQ and local authorities grant a variance to allow the setback from the road to be reduced from 500 to 200 feet Eliminates risks associated with off-site hauling, truck traffic Greater potential for groundwater migration during CCR removal Engineering challenges for CCR dewatering, excavation, and staging 9 years $799M Ash pond stays open for 9 years (1 year design/permit/construct, remaining transport), increases safety risk, and results in prolonged duration for dewatering/water treatment Safety and community risks from excavating and over-theroad hauling due to significant volume and multi-year duration removal project (150 trucks per day each way for 8 years; truck leaving site approximately every 3 minutes for 10 hours per day Monday through Friday) Truck traffic may result in increased noise, emissions, traffic congestion, vehicle accidents Greater potential for groundwater migration during CCR removal ES-9

14 Table ES-5 (cont.): Summary of Closure Options for Possum Point Power Station Closure Option Est. Time Frame Est. Cost (1) Implementation Considerations and Off-Site Commercial Landfilling by Rail and Off-Site Commercial Landfilling by Barge and Trucking 9 years $1.11B Ash pond stays open for 9 years (2 years design/permit/construct, remaining transport), increases safety risk, and results in prolonged duration for dewatering/water treatment Safety and community risks from excavation and rail hauling due to significant volume and multi-year duration removal project (180 railcars per week for 7 years) Reduced hauling risks for rail vs. trucking Greater potential for groundwater migration during CCR removal 15 years $1.7B+ Ash pond stays open for at least 15 years (4 years design/permit/construct, remaining transport), increases safety risk, results in prolonged duration for dewatering/water treatment Safety and community risks from CCR removal; excavation and construction noise and traffic Option involves trucking of CCR material to barge facility and once barge reaches its destination, CCR material would be trucked an additional 18 miles on public roads to landfill Virginia regulations require sealed containers that would need to be loaded onto and off of barges by crane, requiring infrastructure construction at both ends Engineering risks for CCR dewatering and excavation Lower groundwater risks after removal is completed; higher groundwater risk during removal Closure-in-Place with Potential Groundwater Corrective Measures 3 to 5 years $137M to $418M No impacts for CCR removal or off-site hauling Lowest risk for safety, community, schedule, and cost Lower groundwater migration potential for CCR remaining in place once closure is complete, which is addressed by corrective measures Includes cost range for corrective measures 2-year corrective measure construction duration Estimated 10- to 30-year duration for groundwater corrective measures (1) All costs in this report are Class 5 estimates (+100%, 50%) and represent opinions of probable cost based on information available at the time of this study. is not responsible for any variance from costs presented in this document or actual prices and conditions obtained. B = billion; CCR = coal combustion residuals; DEQ = Virginia Department of Environmental Quality; M = million; NA = not applicable ES-10

15 Table ES-6: New Regional Landfill Summary Closure Option Est. Time Frame Est. Cost (1) Implementation Considerations New Regional Off-Site Landfill for Ponds at Bremo, Chesterfield, and Possum Point 21 years $4.15B Would be located in a centralized area to accept materials from all Dominion ash ponds Ash ponds stays open for up to 20 years (6 years design/permit/construct new landfill, remaining time to transport from all three sites), increases safety risk, and results in prolonged duration for dewatering/water treatment Duration will exceed CCR closure requirements of 15 years at Chesterfield Power Station Safety and community risks from excavation and over-theroad hauling due to significant volume, multi-year duration removal project (up to 150 trucks/day each way from all 3 stations for 15+ years) Truck traffic may result in increased noise, emissions, traffic congestion, vehicle accidents Construction of new landfill and hauling ash to new location will affect local communities Extensive permitting and design required (1) All costs in this report are Class 5 estimates (+100%, 50%) and represent opinions of probable cost based on information available at the time of this study. is not responsible for any variance from costs presented in this document or actual prices and conditions obtained. Costs are for one landfill facility that will accept all ponded ash from Bremo, Chesterfield, and Possum Point Power Stations; includes permitting, design, construction of new landfill, along with excavation, materials handling, trucking from the stations and placement into the new landfill Chesapeake Energy Center not included as alternative is not practical due to small volume of CCR B = billion; CCR = coal combustion residuals In accordance with the CCR Rule, closure of ash ponds greater than 40 acres, which includes Bremo North Ash Pond, Chesterfield Lower and Upper Ash Ponds, and Possum Point Ash Pond D, must be completed within 15 years (5-year base period plus up to five extensions in 2-year increments). For ponds less than 40 acres (Chesapeake Bottom Ash Pond), closure must be completed within 7 years (5-year base period plus one 2-year extension). Exhibit ES-1 shows the estimated timelines for the closure options at the four power stations compared to the required CCR Rule timelines. Note that some of the closure options are estimated to take longer than 15 years. ES-11

16 CCR Rule closure m 0 ~ ~ N ~ ~ ~ ~ ~ ~ ~ ~ ~ M ~ ~ ~ ~ ~ M ~ ~ ~ N N N N N N N N N N N N N N N N N N N N N N and landfilling off site, removal by truck and landfilling off site, removal by rail and beneficial use and landfilling on site and landfilling off site, removal by truck and landfilling off site, removal by rail and landfilling on site and landfilling off site, removal by truck and landfilling off site, removal by rail and landfilling off site, removal by barge and landfilling at new off-site landfill ~ Design/ regulatory approval ~ Construction ~ Operation.. Duration beyond CCR closure requirements (Note: Solid line represents minimum duration and dotted line represents maximum duration for beneficial use technolog ies) Exhibit ES-1: Closure Implementation Timeline ES-12 This page revised after the December 1, 2017 publication